The present invention relates to an apparatus for servicing refrigeration systems and particularly to a system which integrally includes a flow control for the sampling of refrigerant type.
When vehicles are brought to a service center for professional servicing of the air conditioning system, frequently the system has had refrigerant leaks and losses in the past and either the vehicle owner or service center that does not have the proper equipment or refrigerant has mixed different types of refrigerant or added the wrong refrigerant to the system. The preferred refrigerant now in use is the environmentally approved R-134. Still available, however, is the previously used R-12 refrigerant and R-22 refrigerant is used in home air conditioning systems. Frequently, a vehicle owner will mix the wrong types of refrigerant or purchase a blend of refrigerants from a retail store in an attempt to recharge the system, which, having needed to be recharged, leaks refrigerant and does not operate satisfactorily with the wrong or blended refrigerant. Thus, when a vehicle finally reaches a service center with proper equipment for professional maintenance of the air conditioning system, frequently refrigerant contained in the system is a mix and of an unknown nature. Thus, it is necessary and desirable to identify whether this problem exists and, if so, completely new refrigerant of the proper type is employed for charging the system.
In order to detect the refrigerant in a vehicle refrigerant circuit, a sample is taken directly from the vehicle coupled to the servicing instrument. Also, it is useful to periodically monitor the recovery tank of the system to make certain it has not become contaminated. In the past, a stand-alone flow control system has been provided which provides a metered orifice and pressure control switch to allow the sampling of refrigerant from the servicing unit to a refrigerant identification instrument, such as a Neutronics ACR2KID, through an oil separator. The oil separator protects the instrument from damage due to oil in the refrigerant being sampled from entering the instrument. The disadvantages of this prior art system is that it is an add-on, stand-alone unit requiring its own power source and is somewhat prone to incorrect installation by the service technician to protect the refrigerant identification unit. Further, this only permits testing of refrigerant on the low side (vapor) of the air conditioning servicing unit.
There remains a need, therefore, for a protection system for refrigerant identification detectors and one which is integrated with the refrigerant recovery and recharging system and one which allows sampling of refrigerant, either from the high or low pressure sides of the recovery system and also from the main refrigerant tank.